Curcumin inhibits pro-inflammatory mediators and metalloproteinase-3 production by chondrocytes

Objective and Design. This study aims to investigate the effects of curcumin (Cur) on the production of inflammatory mediators and on the extracellular matrix proteins metabolism by articular chondrocytes.
Methods. Human chondrocytes in alginate beads and human cartilage explants were cultured in the absence or in the presence of interleukin (IL)-1beta(10-11 M) and with or without Cur (5 to 20 µM). Nitric oxide (NO) synthesis was measured by Griess spectrophotometric method, prostaglandin (PG) E2 by a specific radioimmunoassay and IL-6, IL-8, aggrecan (Agg), matrix metalloproteinase (MMP)-3 and tissue inhibitor of metalloproteinase (TIMP)-1 by specific enzyme-amplified immunoassays. Proteoglycans degradation was evaluated by the release of 35S-glycosaminoglycans (GAG) from human cartilage explants.
Results. In alginate beads and cartilage explants models, Cur inhibited in a concentration dependent manner the basal and the IL-1beta stimulated NO, PGE2, IL-6, IL-8 and MMP-3 production by human chondrocytes. The TIMP-1 and the Agg productions were not modified. In basal condition, 35S-GAG release from cartilage explants was decreased by Cur.
Conclusions. Cur was a potent inhibitor of the production of inflammatory and catabolic mediators by chondrocytes, suggesting that this natural compound could be efficient in the treatment of osteoarthritis.